For this purpose, a vehicle steering unit and an axle steering module for a vehicle steering unit are known from the publication DE 101 14 600 A1, which have such a steering actuation apparatus, in particular a steering hand wheel, and in each case have an electronic control assembly for controlling a steerable wheel, located on the right and left on a vehicle body, of a wheel pair of a steerable vehicle axle. In addition, at least one target value generator for a steering angle to be set, which is operable by the steering actuation apparatus, and an actual value generator, which at least registers one of the steering angles of the vehicle wheels, of a central control unit are known from the publication.
The vehicle steering unit and the associated method known from DE 101 14 600 A1 accordingly disclose an electronic method, which specifies and sets the respective steering angle of the steerable wheels with the aid of a central control unit, the method disclosed therein allowing, in the event of failure of a controller of one of the steerable wheels, the steering angle of the still functional controller to be transmitted to the control assembly of the failed controller by a data transmission.
In the known vehicle steering units and axle steering modules, the electronic steering stops for the steerable wheels within the surrounding wheel case are specified by so-called soft stops, which thus limit the turning circle of a vehicle, since they do not use the complete wheel clearance via the vehicle body. The wheel clearance differs depending on the lateral acceleration/travel velocity at which the vehicle travels. Normally, the wheel clearance is greater in the case of slow travel with low lateral acceleration than in the case of travel with high lateral acceleration. However, mechanical steering ranges are designed for this purpose so that the wheel moves dynamically freely, i.e., the theoretically smallest possible turning circle, for example, at a standstill of the vehicle, cannot be achieved. In addition, so-called EPS specifications (electrical power steering specifications) ensure that the electronic steering stops or soft stops only limit a further steering movement close to the mechanical end stop of the steering unit by reducing the steering support and even by active counter steering. This has the result that the turning circle of the vehicle is restricted for safety reasons.
At least one object is to provide a method for vehicle steering using a vehicle steering device, which improves the turning capability of the vehicle, in particular for parking. In addition, other objects, desirable features and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.